Numerous devices have been suggested over the years to prevent unauthorized uses of trailers. Some devices are designed to prevent someone from inserting a vehicle tow ball inside the ball socket of the trailer hitch of an unattended trailer. Examples are disclosed in U.S. Pat. No. 3,434,741 (Grant) of 1969, U.S. Pat. No. 3,526,110 (Foote) of 1970, U.S. Pat. No. 4,291,557 (Bulle et al.) of 1981 and U.S. Pat. No. 4,581,908 (Bulle et al.) of 1986, to name just a few.
Other devices are designed to prevent the trailer hitch from being detached from the trailer tow bar, thereby preventing someone from using another trailer hitch and towing the trailer away. See for instance U.S. Pat. No. 7,635,143 (Pappalardo) of 2009.
Still, some devices are designed to prevent someone from detaching the trailer hitch from a vehicle tow ball to which it is attached. See for instance U.S. Pat. No. 3,770,298 (Phillips) of 1973.
Existing devices suffer from one or more deficiencies, particularly in terms of simplicity, ease of use and versatility. Accordingly, there is still room for improvements in this area of technology.